Trim four heads of chickory, boil until half cooked, then drain and mince very finely. Mix well with this two ounces each of flour and butter and a sprinkling of pepper, salt and mace. Next place the mixture in a saucepan with a quart of white stock and a cupful of boiling milk. Cook carefully for an hour. Now beat the yolks of two eggs in half a cupful of milk, add to the soup as soon it has gone off the boil, and strain the whole through a fine sieve. Serve as quickly as possible.